Lathe carriage feed mechanism



April 13, 1943. A CARTER 2,316,403

LATHE CARRIAGE FEED MECHANISM Filed June 8, 1940 3 Sheets-Sheety l 29 zy l 5554; V13

MII/ll April 13, 1943 L. A. ARTER LAT'HE CARRIAGE FEED MECHANISM 5 Sheets-Sheet 2 Filed June 8. 1940 April 13, 1943. L, A. CARTER LATHE CARRIAGE FEED MECHANISM Filed June 8, 1940 3 Sheets-Sheet' 5 i /IV /E/Vrolre:

Patented Apr. 13, 1943 UNETED STATE-1Sy PATENT OFFlCE LATHE CARRIAGE FEED MECHANESM Lionel A. Carter, Webster Groves, Mo., assigner to Lehmann Machine Company, St. Louis, Mo., 'a corporation lof Missouri MaplioationY June 8, 1940, Serial No. 339,471

(Cl. SIZ- 21) .11 Claims,

This invention relates to carriage feeding mechanisms for lathes or other machine tools, particularly rapid traverse mechanisms of the type wherein a unidirectional feed screw havig intersecting right and left hand threads eX- ends through right and left hand nuts journaled i the carriage and individually operable gripying devices are provided for holding the respective nuts against rotation, whereby the gripped nut moves along the rotating feed screw and carries the carriage with it. The invention lhas for its principal objects the utilization of fluid pressure for operating the nut gripping devices, to prevent rotation of the carriage handle during the operation of the rapid traverse mechanism and thus prevent injury to the operatcr by said handle, and to provide for simplicity and cheapness of construction, ease of'operation Iand compactness of design. The invention consists in the fluid pressure controlled rapid traverse mechanism and in the parts and arrangements and combinations of parts hereinafter described and claimed.

In the accompanying drawings, which form part of this specification and wherein like symbols refer to like parts wherever they occur,

Fig. 1 is a rear elevation of a portion of a lathe equipped with uid pressure controlled rapid traverse mechanism embodying my invention,

Fig. 2 is an enlarged fragmentary vertical section on the line 2--2 in Fig. 1, showing the worm drive gearing for the feed screw,

Fig. 3 is a vertical section on the line 3-3 in Fig. 2,

Fig. 4 is an enlarged fragmentary vertical section on the line 4-4 in Fig. 1,

Fig. 5 is a vertical longitudinal section on the line 5-5 in Fig. 4, l

Fig. 6 i-s an enlarged vertical fragmentary section on the line 4-4 in Fig. 1,

Fig. 7 is a fragmentary front elevation of the lathe,

Fig. 8 is an enlarged vertical section on the line 8-8 in Fig. 7,

Fig. 9 is a vertical section on the line 9-9 in Fig. 8,

Fig. 10 is a horizontal section on the line I II-I D in Fig. 8; and

Fig. l1 is an enlarged vertical section similar to Fig. 9.

In the accompanying drawings, my invention` i shown embodied in a lathe comprising a bed i and a carriage 2 slidable along said bed on therefrom that overhangs the front face of the bed I. Hand movement of the carriage 2 along the way 3 is through a hand wheel 5 having a handle S, a horizontal cross shaft 'I journaled in suitable bearings 8 and 9 in the front and rear walls I l) and II, respectively, of the carriage apron 4, a pinion I2 fixed to said shaftl between; the apron walls, a gear I3 fixed to a countershaft I4 also journaled in said apron walls and a pinion I5 fixed to said countershaft and cooperating with Aa rack I5 fixed to and disposed longitudinally of the lathe bed I. The cross shaft 'l' extends outwardly beyond bearing 8 in the front wall of the apron t; and the hand wheel 5 has an elongated chambered hub ,portion I'I supported at its front and rear ends von said shaft for both rotary and axial sliding movement relative thereto. The hub I1 of the hand wheel 5 is normally voperatively connected to the cross' shaft 'I to rotate the same by means of a clutch including clutch elements I8a on the inner end of a cap I8 for the outer end of said hub and clutch elements 'Ilia on the flanged outer end I9b of a sleeve I9 that is keyed to said shaft and is held thereon against axial sliding movement relative thereto between an abutment shoulder'la thereof and a nut 20 thereon. The clutch elements -I8a of the hand wheel 5 are normally held in engagement with the clutch yelements.

IQa of the sleeve I9 by means of a coil compression spring 2| that is located in the hub I 'I of said hand wheel and is sleeved von the cross shaft I2 with one end seated against the inner end of said hub and the other end bearing against a thrust bearing 22 that seats against the outer end flange I9b of said sleeve. By this arrangement, the .hand wheel' 5 is normally lclutched to the cross shaft 'I to rotate the same, but may be shifted outwardly -along said shaft against the pressure of the spring 2|, in a 'manner hereinafter described, to disengage the clutch elements I8a and IQa and thus prevent rotation of said hand wheel by said cross shaft due to the gear connection I2, I3 and I5 with the rack I6 when the carriage 2 is moved along the bed I by means other than said hand wheel.

The lathe is provided with means for effecting a rapid power feed of the carriage '2 independently of the .manual feed herein-before described and the usual feed rod and lead screw carriage feeds (not shown). As kshown in the drawings this power rapid. traverse or feed mechanism comprises a horizontal unidirectional screw 23 that has intersecting right and left hand screw threads 24 Aand 25, respectively,

and extends longitudinally of the lathe along the rear side thereof through a horizontal opening 26a provided therefor in a bracket 26 that` 3| in the housing 30 is a horizontal shaft.

32 that extends crosswise of the feed screw 23 and has a worm 33 that intermeshes with a worm gear 34 that is fixed to said feed screw between the bearings 29 therefor. The worm shaft 32 has a pulley 35 xed thereto outside of the housing and this pulley is driven through an endless belt 36 from the driving pulley 31 of an electric motor 38 that is bolted to the adjacent end of the lathe bed l.

The right and left hand threaded feed screw 23 extends through and cooperates with longitudinally spaced right and left hand sleeve nuts 39 and 40, with poured interior linings 39a and 40a, respectively, of Babbitt metal. These nuts are carried by the depending bracket 26 of the carriage 2, each nut being journaled in suitable ball bearings 4I provided therefor in the opening 26a in said bracket for normal free rotation with the feed screw 23 and held by said bearings against endwise movement in said bracket. Each of the nuts 39 and 40 may be held against rotation in the carriage bracket 26 by means of a gripping or braking device comprising a split sleeve 42 which is mounted around said nut in the opening 26a of the carriage bracket 26 and is provided with a suitable friction lining 43 adapted to engage the outer peripheral surface of said nut.

The split gripping or clamping sleeve 42 for each of the sleeve nuts 39 and 40 is provided on opposite sides of its split portion with abutment shoulders 44, one engaged by the inner end of stop screw 45 and the other by the inner end of the rod or plunger extension 46a of a piston 46, The screw 45 is threaded into the carriage bracket 26 on the inner or bed opposing side thereof and is provided with a lock nut 45a; and the piston 46 works in a bore 41 that leads inwardly from the other or outer side of said bracket in axial alinement with said screws. The rod or plunger portion 46a of the piston 46 is slidably supported in the inner end portion of the bore 41; and said bore has an enlarged or counterbored outer end portion that is covered by a leather diaphragm 48 to form a chamber or cylinder 49 for said piston. This diaphragm is clamped flatwise to the carriage bracket 26 by means of a clamping plate 50 that is removably secured to said bracket cap screws 5I. A coil compression spring 52 surrounds the plunger 46a of the piston 46 between the inner end compression spring of the latter and an annular seat in the bore 41 and thus tends to force said piston outwardly in the chamber or cylinder 49.

The split brake sleeves for nuts 39 and 40 are closed thereupon by fluid, preferably oil, acting against the outer faces of the diaphragms 48 which close the chambers or cylinders 49 for the operating pistons 46 for the respective sleeves. This fluid is contained in a` closed chamber or reservoir 53a formed in a housing aeiaio 53 secured to the front face or wall l0 of the carriage apron 4 below the cross shaft 1. The oil is conveyed to the respective diaphragms 48 through pipes or conduits 55 that lead down- Wardly from vertical bores 54 in the bottom of the oil chamber 53 thence through the front Wall l0 of the carriage apron 4, thence upwardly through said apron, thence rearwardly across the carriage 2 and thence downwardly along the rear face of the carriage bracket 26 where they open into holes 56 formed in the clamping plates 50 opposite chambers 49 for the respective pistons 46 working in the bores 50, which communicate with the conduits or pressure lines leading to the diaphragms 48 of the respective cylinders 49, are pistons or plungers 51 for exerting pressure on the oil in said lines. Each of these pistons extends downwardly through the oil reservoir 53 with its lower portion snugly fitting within the bore 54 in the bottom of said reservoir and with its upper portion slidably supported or guided in a vertical bore 58 provided therefor in the top wall of said reservoir. Each plunger 51 has an axial bore or passageway 59 leading upwardly from the lower end thereof and communicating in the raised or inoperative position of the plunger with the reservoir 53a through a lateral port 6|. Each plunger 51 has a second lateral port 60 that opens into the reservoir 53a above the port 6l. The axial passageway 59 is provided above the lower port 6I with a downwardly opening ball check valve 62 which is yieldably held against its seat by a coil compression spring 63 interposed between said valve and a threaded plug 64 having an axial passageway 65 therethrough for establishing communication between the axial passageway 59 and the bore 54 leading from the bottom of the oil reservoir 53a. Each plunger 51 is normally held in raised position; With both lateral ports and 6I thereof in communication with the reservoir 53a, by means of a coil compression spring 66 which surrounds said plunger with one end seated on the bottom of the reservoir 53a and with the other end bearing against the underside of a collar 61 that is pinned on said plunger and is normally held in abutting relation to the top wall of said reservoir by the expansive action of said spring.

The two plungers 51 are selectively depressed to exert pressure on the oil in the conduits 55 and thus close the nut gripping sleeves 42 by means of a control lever or handle 68 having a hub portion 69 journaled on the reduced outer end portion 8a, of the outer end bearing 8 for the cross shaft 1 between the front wall I0 of the carriage apron 4 and the hub I1 of the hand wheel 5. The bearing 8 has a flange 8b at its inner end that abuts against the inner face of the apron wall i0 and an annular plate 10 is sleeved on said reduced portion of said bearing in abutting relation to the shoulder formed thereby and the outer face of said apron and is secured to said flange by cap screws 1I that pass through said annular plate and wall and are threaded into said flange to thereby secure said bearing in said wall against axial movement. The hub portion 69 of the iiuid control handle 68 has a downwardly opening cross groove 12 in the periphery thereof; and a pin 13 is fixed in said hub and extends longitudinally thereof across said groove This pin 13 works in a notch 14 in the upper, for vertical swinging movement crosswise of said pin on a horizontal pivot pin 16 mounted in the plunger supporting and oil containing housing 53,

The pivot pin for 'the rock lever l5 is located midway between the upper end portions of the two plungers 5l, and said rock lever is provided on opposite sides rof said pivot with flat overhanging cam faces or'shoulders 'Il disposed in abutting relation to the upper ends of the respective plungers. By this arrangement, in the upright or neutral position of the hand lever 68, both plungers 5l are held by their supporting springs 66 in uppermost position and no pressure is applied to the fluid in the conduits 55 leading to the diaphragms 4S for operating the respective brake sleeve actuating pistons 5, thereby lpermitting the two nuts S9, 40 to rotate freely in the yapron 4 with the feed screw 23 without imparting any movement to the carriage 2.- When the hand lever 58 is swung in the direction in which it is desired to move the carriage, the rock lever 75 is swung by the pin 13 on the hub 69 of said lever and depresses the plunger 51 that will exert pressure on the oil in the conduit 55 which leads to the piston operating diaphragm 8 that closes the gripping sleeve 42 for the particular nut 39 or 15, which when held stationary will travel along the feed screw 23 and move the carriage 2 in the desired direction. When the iiuid control handle 38 is released, the spring 66 forces the depressed plunger 5l upwardly, thereby returning said handle to upright neutral position and relieving the pressure on the iiuid and thus permitting gripping device i2 to open and permit the nut to turn with the feed screw without imparting any movement to the carriage.

When the fluid control lever 68 is operated to depress one of the plungers 5l, the hand wheel 5 is automatically disconnected from the cross shaft l2 so that the rotary movement imparted to said shaft by the travel of the pinion i5 along the rack l5 during the rapid traverse feed of the carriage 2 will not spin said hand wheel and cause the handle G thereof to strike and injure the operator. This automatic disengaging means for the hand wheel 5 comp-rises one or more pins 18 that are slidabiy mounted in longitudinal bores provided therefor in the hub 69 of the hand lever 65 and are adapted in the neutral position of said lever to engage recess Ilia, provided therefor in the hub opposing face of the annular retaining plate 7G for the front bearing 8 of the cross shaft I2. The inner ends of these pins F3 seat in the notches and their outer ends abut against an annular plate 'i9 secured by screws 8i) to the outer end of the hub 59 of the lever 6B, the inner end of the hub 6 of `the hand wheel 5 being held lagainst said plate by the clutch engaging spring 2l. In the neutral position of the control handle 68, the pins '13 seat in the recesses la and thus releasably hold said handle in said position. When, however, the lever 63 is swung in either direction to bring the rapid traverse into operation, the pins 'IS rotate with the hub 69 of said lever and are thus forced out of the notches and pressed endwise against the annular plate 'i9 fixed to said hub and thereby push the hub I1 of the hand wheel 5 outwardly along the cross shaft 'l far enough to disengage the clutch elements Ia of the hub cap from the clutch elements ISa of the clutch sleeve i9 fixed-to said shaft. Thus, the hand wheel 5 is automatically uncoupled from the cross shaft 'l whenever the rapid traverse mechanism is brought into operation and cannot be rotated by said shaft. n

In the 'raised'or' inoperative position of the plungers 51, the lowermost ports 6| therein establish communication between the reservoir 53a and the lines 54 leading to the daphragms 48 for the operating piston 46 for the nut gripping devices 42 and thus serve to prevent any inequalities in pressure in said reservoir and pipe lines due to leakage or expansion of the operating fluid, When the plungers are depressed, the upper ports t9 therein are still in communication with the reservoir 53a and the ball check valves 52, which prevent return flow of the fluid from the pipe and lines 55 to said reservoir, are adapted to unseat and permit iiuid that has leaked from said vline around said plungers into said reservoir to re-enter the line through said upper ports.

VThe split brake sleeves 42 are prevented from turning in the carriage bracket 26 by the stop screws 45 and the plunger extensions 45a of the closing pistons IE6; and said stop screws may be adjusted to take up wear of said sleeves or the nuts gripped thereby. The springs 52 serve to supplement the actions of the 'plunger supporting springs 6B in releasing the brake sleeves 42 when the uid control handle 63 is released.

The hereinbefore described arrangement admits of considerable modification without departing from the invention. Therefore, I do not wish t0 be limited to the precise arrangements shown and described.

What I claim is:

I. A lathe carriage feed mechanism comprising a unidirectional feed screw having right and left hand threads, nuts journaled in the carriage and cooperating with the respective threads, uid pressure actuated means mounted entirely on and movable with said carriage for selectively gripping said nuts to said carriage, manually operable meansfor moving said carriage including a shaft journaled in said carriage, a rotary handle rotatable about the axis of said shaft and a normally engaged clutch connection between said shaft and said handle, and a single control means for said iiuid pressure actuated means and said clutch for automatically disengaging said clutch Awhenever said control means is operated to cause the fluid pressure actuated means controlled thereby to grip said nuts, said control means including a control 'lever mounted on said carriage for pivotal movement about the axis of said shaft.

2. A carriage feed mechanism comprising a feed screw, a nut journaled in said carriage and cooperating with said screw, means for gripping said nut to said carriage, and fluid pressure means for 'actuatingV said nut gripping means, said fluid pressure means including a iiuid containing reservoir mounted yon and movable with said carriage, a pressure responsive device mounted in said carriage for operating said nut gripping means, a conduit sustained by and movable with said carriage and leading from said reservoir to said pressure responsive device, a plunger working said conduit for exerting pressure on the iiuid therein in the direction of said pressure re-` sponsive device, and a control member mounted in said carriage for actuating said plunger.

3. A carriage feed mechanism comprising a feed screw having right and left hand threads, nuts journaled in said carriage and cooperating with the respective threads, a separate device for gripping each of said nuts to said carriage, and fluid pressure means for selectively operating the respective nut gripping means, said fluid pressure means including a iiuid containing res4 ervoir sustained by and movable with said carriage, a separate pressure responsive device mounted in said carriage for operating each oi said nut gripping devices, a separate conduit sustained by and movable with said carriage and leading from said reservoir to each of said pressure responsive devices, a separate plunger in each of said conduits for exerting pressure on the fluid therein in the direction of the pressure responsive devices associated therewith, and a single control member mounted in said carriage for selectively actuating said plungers.

4. A lathe carriage feed mechanism comprising a unidirectional feed screw having intersecting right and left hand threads, nuts journaled in said carriage and cooperating with the respective threads, means for selectively gripping said nuts to said carriage, and fluid pressure operated means for selectively operating the respective nut gripping means, said fluid operating means including a uid containing reservoir in said carriage, separate pressure responsive devices mounted in said carriage for operating the respective nut gripping devices, separate conduits leading from said reservoir to the respective pressure responsive devices, separate plungers in the respective conduits for exerting pressure on the uid therein in the direction of the pressure responsive devices associated therewith, a single control lever mounted in said carriage for selectively actuating said plungers, manually operable means for moving said carriage including a shaft and a handle having a normally engaged clutch connection therewith, said control lever and handle being mounted on said carriage for pivotal movement about a common axis, and means operable by the movement of said control lever to nut gripping position for automatically disengaging said clutch connection.

5. A carriage feed mechanism comprising a feed screw having right and left hand threads, nuts journaled in said carriage and cooperating with the respective threads, a separate device for gripping each of said nuts to said carriage, and uid pressure means for selectively operating the respective nut gripping means, said uid pressure means including a uid containing reservoir in said carriage, a separate pressure responsive device mounted in said carriage for operating each of said nut gripping devices, a separate conduit leading from said reservoir to each of said pressure responsive devices, a separate plunger in each of said conduits for exerting pressure on the fluid therein in the direction of the pressure responsive devices associated therewith, and a single control member mounted in said carriage for selectively actuating said plungers, each of said plungers having a passageway opening through the working end thereof into the conduit associated therewith and also opening through the side of said plunger through two ports spaced apart longitudinally thereof, and a check valve in said passageway between said ports and opening in the direction of the working end of said plunger, both of said ports communicating with said reservoir in the inoperative position of said plunger and the port nearest the working end of said plunger being covered by said conduit during the working stroke thereof.

6. A carriage feed mechanism comprising a feed screw having right and left hand threads, nuts journaled in said carriage and cooperating with the respective threads, split sleeves nonrotatably mounted in said carriage for gripping the respective nuts, and uid pressure means for closing said split sleeves upon said nuts, said iiuid pressure means including a single fluid containing reservoir in said carriage, separate pressure responsive devices cooperating with said split sleeves to close the same upon the respective nuts, separate conduits leading from said reservoir to the respective pressure responsive devices, plungers working in said conduits for exerting pressure on the fluid therein in the direction of said pressure responsive devices and a single control member for selectively actuating said plungers.

7. A carriage feed mechanism comprising a feed screw having right and left hand threads, nuts journaled in said carriage and cooperating with the respective threads, separate split sleeves non-rotatably mounted in said carriage around the respective nuts, separate pressure responsive devices in said carriage and cooperating with said split sleeves to close the same upon the respective nuts, and a fluid pressure system for actuating said pressure responsive devices including a single reservoir in said carriage, separate conduits leading from said reservoir to the respective pressure responsive devices, separate plungers working in the respective conduits for exerting pressure on the uid therein in the direction of said pressure responsive devices, a single control lever mounted in said carriage, a rock lever pivoted in said carriage and having cam faces disposed in abutting relation to the outer ends of the respective plungers, an operative connection between said rock lever and said control lever for rocking said rock lever in one direction to actuate one plunger and in the opposite direction to actuate the other plunger, and means for normally holding both of said plungers and said single control lever in inoperative position.

8. A carriage feed mechanism comprising a feed screw having right and left hand threads, nuts journaled in said carriage and cooperating with the respective threads, separate split sleeves nonrotatably mounted in said carriage around the respective nuts, separate pressure responsive devices in said carriage and cooperating with said split sleeves to Close the same upon the respective nuts, and a uid pressure system for actuating said pressure responsive devices including a single reservoir in said carriage, separate conduits leading from said reservoir to the respective pressure responsive devices, separate plungers working in the respective conduits for exerting pressure on the fluid therein in the direction of said pressure responsive devices, a single control lever mounted in said carriage, a rock lever pivoted in said carriage and having cam faces disposed in abutting relation to the outer ends of the respective plungers, an operative connection between said rock lever and said control lever for rocking said rock lever in one direction to actuate one plunger and in the opposite direction to actuate the other plunger, and means for normally holding both of said plungers and said single control lever in inoperative position, each of said pressure responsive devices comprising a piston mounted in a chamber in said carriage crosswise of said sleeve with one end in abutting relation thereto on one side of the split therein and a diaphragm closure for said chamber opposite the other end of said piston and adapted to be operated by the pressure of the iiuid in the conduit leading to said pressure responsive device, and a member mounted in said carriage in abutting relation to said sleeve on the other side of the split therein for preventing rotation of said sleeve and for taking up play between the cooperating surfaces of said sleeve and the nut cooperating therewith.

9. In a lathe including a bed having a rack and a double reversely threaded screw disposed along said bed, a carriage including a pinion adapted to cooperate with said rack, right-hand and lefthand nuts adapted to cooperate with said screw, a hand wheel for rotating said pinion, a hand lever for connecting said nuts alternately to said carriage, a clutch between the hand wheel and the pinion, and an inter-connection between the hand lever and the hand wheel clutch for disconnecting said clutch when either of the nuts is coupled.

10. In a lathe, a bed, a right-hand and lefthand screw, a rack disposed along the fbed, a carriage on the bed, means for connecting the carriage to the screw, a pinion engaging said rack, a hand wheel for rotating said pinion, a clutch between the hand wheel and the pinion, a control lever located immediately above the hand wheel at the front of the carriage, said hand lever connected to the means for connecting the carriage to the screw, and a device between the said lever and said hand wheel clutch for disconnecting the clutch when the hand lever is in power carriage traversing position.

11. A carriage traversing `mechanism for moving a carriage along the bed of a lathe, the bed including a rack and a power driven reversely threaded screw, a pinion in the carriage engaging the rack, a hand wheel forrotating the pinion, means for connecting the carriage to the screw, a control lever mounted directly above and adjacent the hand wheel and connected to said lastnamed means, a clutch between the pinion and hand wheel, means extending down from the control lever to the clutch for disconnecting the clutch When the power coupling means is connected, and means for automatically balancing the hand lever in position, uncoupling the power and connecting the hand wheel and clutch.

LIONEL A. CARTER.

- CERTIFICATE 0F ooRREoTIoN.

Patent No. 2,51,Li05. April 15, 1915.

LIOBEL A CARTER It is herebT certified that error appears in the printed specification of' the above numbered patent requiring correction as follows: Page 2, seoond column, line 7 2, after the word "upper," insert --free outer end of a rook lever "('5 that4 is journaled; page 5, second Column, line 61|., before "said" insert --in; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 29th day of June, A. D. 1914.5

Henry Van Arsdale,

(Seal) Acting Commissioner of Patents. 

